public class Test {
    public static void main(String[] args) {
        person person=new person();
        person.start();
        Dog dog=new Dog();
        dog.start();
    }
}
class person extends Thread{
    @Override
    public void run() {
        for (;;){
            System.out.println("wdmnd");
        }
    }
}
class Dog extends Thread{
    @Override
    public void run() {
        for (;;){
            System.out.println("汪汪汪");
        }
    }
}